Hello there,
I tried to install solaris 11 Express to my new Acer 4740 laptop. Everything just went fine until I found that my wireless driver is not recognized. The following message appeared in Device Driver Utility
Device: "Atheros Communications Inc. AR9287 Wireless network Adapter"
Driver: "Misconfigured: [arn]"
I tried to install either arn or ath drivers but both failed and shows the same result.

The arn manpage does not say it supports the AR9287 chip, but it does work with older 9280 chipsets. It looks like bug 6967498 was opened requesting support for the AR9287:
http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6967498